Characteristic features of the singlet–triplet mechanism of the electron spin polarization

Abstract

Characteristic features of net chemically induced dynamic electron spin polarization (CIDEP) P_n in triplet–radical (TR) quenching are analyzed in detail within the framework of a general model that enables one to analyze CIDEP both numerically and analytically. This model also makes it possible to accurately describe the nonadiabatic transitions between the terms of the TR-pair spin Hamiltonian that lead to CIDEP generation. The proposed theory yields a simple analytical dependence of P_n on the parameters of the model. In particular, it is shown that, within a wide region of parameters, the dependence of P_n on the coefficient of relative TR diffusion D_r is described by a simple linear relation: \(P_n^{ - 1}\left( {{D_r}} \right) = {Q_0} + \overline {{q_n}} {D_r}\) (with Q₀ and \({{q_n}}\) independent of D_r). It is also demonstrated that the numerical and analytical results obtained are very useful in analysis of experimental data, as demonstrated by analyzing the experimental dependence of P_n on D_r.